Gaknett l



(No Model.)

G. L. HILLS. MIRRR.

Patentd M3436, 1894.`

UNTTnD STATES MIRROR.

SPECIFICATION forming part of Letters Patent No. 516,092,

dated March 6, 1894.

Application filed December l, 18 93 V Serial No. 492,460. (No model.)

To @ZZ whom it may concern:

Be it known that I, GARNETT L. HILLS, a citizen of the United States, residing at Washlngton, in the District of Columbia, have inyented certain new and usefullmprovements in Mirrors; andI do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art towhich it appertains to make and use the same.

My invention relates to mirrors, and more particularly to that class of mirrors used by dentists in the examination of the teeth, and known as mouth mirrors.

It is Well known to dentists and manufacturers of mouth mirrors that the limit of usefulness of such mirrors, which would otherwise be indenite, is materially curtailed by reason of their being scratched and practically ruined in ashort time by coming in contact with the burrs and emery wheels employed in cleaning out cavities and finishing fillings.

The object of my invention is to provide a simple and inexpensive means for obviating this difficulty, and this I accomplish in the manner and by the means hereinafter described and set forth in the claims, reference being had to the accompanying drawings, in which Figure l is a detailed perspective view of my improved mouth mirror showing the several parts detached. Fig. 2 is an enlarged sectional view of the mirror proper showing the parts assembled.

Similar numerals of reference indicate corresponding parts in the diderent views.

In the said drawingsthe numerail denotes the ordinary metallic frame or back ot' a mouth mirror, having the handle 2 attached thereto in the usual manner. Retained therein in any suitable manner, as by bending over the edges of the back l, is the mirror glass 3, preferably, but not necessarily, concaved, and having the usual mercury backing et on its rear side. All of these parts are of a construction well known in the art, and differ therefrom only in having the edge or periphery of the back l screw threaded, as shown at 5. The object .of this is to provide a means for attaching thereto a collar 6, as shown.

The said collar is interiorly screw threaded and has an inwardly projecting flange 7 adapted to engage and retain a thin disk of plain glass or other transparent medium 8 on the surface of the mirror glass. Aring or gasket 9, preferably of rubber, prevents access of any moisture between the two glasses. The edge of the collar 6 may be milled it desired to afford a better iinger hold.

It will readily be seen that the glass disk 8 will receive the scratching from the emery wheels, and when rendered useless can be readily and inexpensively replaced by another by simply unscrewing the collar 6, removing the disk, and inserting a new one. The life of the mirror will thus be prolonged for an indefinite period at a triliing expense.

I Wish it to be understood that I do notlimit myself to the precise construction herein shown, as the details thereof may be varied in any suitable manner, the gist of the invention being the employment of the superimposed glass disk to receive the injury usually done to the mirror glass.

Having thus described my invention, what I claim as new, and desire to secure by Letters Patent, is-

1. As an article of manufacture, a mirror consisting of the mirror glass, a superimposed transparent protecting medium, and means for retaining the two together, substantially as set forth.

2. As a new article of manufacture, a mirror consisting of the mirror glass, its containing frame, a transparent protecting medium superimposed upon the glass, and means for retaining the same iu place, substantially as set forth.

3. In a mouth mirror, the combination with the mirror glass and its containing frame, of a glass or other transparent posed upon the mirror glass, and means for retaining the same in place, substantially as set forth.

4. In a mouth mirror, the combination with the mirror glass, and its containing frame screw threaded on its edge or periphery, ofa glass disk superimposed upon the mirror glass, and a screw threaded collar adapted to disk superi ni- IOC engage the threads on the frame and retain glass disk in place, and a packing interposed Io the glass disk in place, substantially as set between the two glasses to prevent access of forth. moisture, substantially as set forth.

5. In a mouth mirror, the combination with In testimony whereof Iafix my signature in 5 the mirror glass, and its containing frame presence of two Witnesses.

screw threaded on its edge or periphery, of a GARNETT L. HILLS. glass disk superimposed upon the mirror Witnesses: glass, a screw threaded collar adapted to en- CHARLES L. GURLEY,

gage the threads on the frame and retain the I WILLIAM B. GURLEY. 

